Phototherapeutic apparatus for focused uvb radiation and vitamin d synthesis and associated systems and methods

ABSTRACT

The present disclosure is directed to a phototherapeutic apparatus for focused UVB radiation and vitamin D synthesis and associated systems methods. In one embodiment a phototherapeutic apparatus can include a housing at least partially defining an irradiation zone, and an ultraviolet (UV) radiation source carried by the housing. The irradiation zone can be configured to accommodate at least a portion of a human patient. The phototherapeutic apparatus can further include a filter between the UV radiation source and the irradiation zone. The filter can be configured to at least substantially remove UV radiation outside of a predetermined spectrum centered at about 297 nm and having a bandwidth of at most 10 nm.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/262,682, filed Jan. 30, 2019, titled “PHOTOTHERAPEUTIC APPARATUS FORFOCUSED UVB RADIATION AND VITAMIN D SYNTHESIS AND ASSOCIATED SYSTEMS ANDMETHODS,” which is a divisional of U.S. patent application Ser. No.13/733,860, filed Jan. 3, 2013, now issued as U.S. Pat. No. 10,226,641,titled “PHOTOTHERAPEUTIC APPARATUS FOR FOCUSED UVB RADIATION AND VITAMIND SYNTHESIS AND ASSOCIATED SYSTEMS AND METHODS,” which claims thebenefit of and priority to U.S. Provisional Patent Application No.61/582,778, filed Jan. 3, 2012, titled “PHOTOTHERAPEUTIC APPARATUS FORFOCUSED UVB RADIATION AND VITAMIN D SYNTHESIS AND ASSOCIATED SYSTEMS ANDMETHODS,” the contents of which are hereby incorporated by reference intheir entireties.

TECHNICAL FIELD

The present technology relates to vitamin D phototherapy, and moreparticularly to phototherapeutic apparatuses for focused UVB radiationand vitamin D synthesis and associated systems and methods.

BACKGROUND

Vitamin D refers to a group of fat-soluble secosteriods that the humanbody can synthesize through adequate exposure to sunlight. Morespecifically, vitamin D₃ is made in the skin when 7-dehydrocholesterolreacts with ultraviolet B (“UVB”) light. Vitamin D can also be absorbedfrom the various dietary sources, such as fatty fish (e.g., salmon andtuna), vitamin D fortified foods (e.g., dairy and juice products), andvitamin D supplements. Once absorbed, the vitamin D travels through thebloodstream to the liver where it is converted into the prohormonecalcidiol. The calcidiol is, in turn, converted into calcitriol (thehormonally active form of vitamin D) by the kidneys ormonocyte-macrophages in the immune system. When synthesized by themonocyte-macrophages, calcitriol acts locally as a cytokine to defendthe body against microbial invaders. Kidney-synthesized calcitriolcirculates through the body to regulate the concentration of calcium andphosphate in the bloodstream, and thereby promotes adequatemineralization, growth, and reconstruction of the bones. Therefore, aninadequate level of vitamin D, (typically characterized by a calcidiolconcentration in the blood of less than 20-40 ng/m²) can cause variousbone softening diseases, such as rickets in children and osteomalacia inadults. Vitamin D deficiency has also been linked to numerous otherdiseases and disorders, such as depression, heart disease, gout,autoimmune disorders, and a variety of different cancers.

Recently, vitamin D deficiency has become a prominent condition due, atleast in part, to increasingly metropolitan populations and theresultant indoor lifestyles that inhibit adequate daily exposure tosunlight for vitamin D production. The growing emphasis on skin cancerawareness and sunscreen protection, which blocks UVB rays, may have alsoincreased the spread of vitamin D deficiency. Additionally, variousenvironmental factors, such as geographic latitude, seasons, and smog,further impede sufficient vitamin D production.

Physicians have recommended vitamin D supplements as a preventativemeasure to increase vitamin D levels. The American Institute ofMedicine, for example, recommends a daily dietary vitamin D intake of600 international units (IU) for those 1-70 years of age, and 800 IU forthose 71 years of age and older. Other institutions have recommendedboth higher and lower daily vitamin D doses. The limitations on dailydosages also reflect an effort to prevent ingesting too much vitamin D,which can eventually become toxic. In contrast, the human physiology hasadapted to significantly higher daily doses of vitamin D from sunlight(e.g., 4,000-20,000 IU/day or more). UVB radiation has been identifiedas a more desirable source of vitamin D because of the ease at whichvitamin D is produced from exposure to sunlight and the body's naturalability to inhibit excessive vitamin D intake through the skin.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present disclosure can be better understood withreference to the following drawings. The components in the drawings arenot necessarily to scale. Instead, emphasis is placed on illustratingthe principles of the present disclosure.

FIGS. 1A and 1B are isometric views of a phototherapeutic apparatus forfocused UVB radiation in an open position and a closed position,respectively, configured in accordance with an embodiment of the presenttechnology.

FIG. 1C is a top view of the phototherapeutic apparatus of FIGS. 1A and1B.

FIG. 1D is an enlarged side view of a focused UVB radiation assembly ofthe phototherapeutic apparatus of FIGS. 1A-1C configured in accordancewith an embodiment of the present technology.

FIGS. 2A and 2B are exemplary graphical representations of relativespectral powers of a UV source before and after UVB filtering,respectively, in accordance with an embodiment of the presenttechnology.

FIGS. 3A-3C illustrate display pages for a phototherapeutic apparatusfor focused UVB radiation configured in accordance with an embodiment ofthe present technology.

FIG. 4 is a block diagram illustrating a method of providing focused UVBradiation for vitamin D synthesis in accordance with an embodiment ofthe present technology.

FIG. 5A is an isometric view of a phototherapeutic apparatus for focusedUVB radiation configured in accordance with another embodiment of thepresent technology.

FIG. 5B is an enlarged partially schematic side view of a focused UVBradiation assembly of the phototherapeutic apparatus of FIG. 5Aconfigured in accordance with an embodiment of the present technology.

FIG. 5C is an enlarged partially schematic side view of a focused UVBradiation assembly for the phototherapeutic apparatus of FIG. 5Aconfigured in accordance with another embodiment of the presenttechnology.

FIG. 6 is an exemplary graphical representation of the relativeradiation intensity of a focused UVB radiation assembly with a metalhalide UV source configured in accordance with the present technologycompared to the relative radiation intensity of the sun.

FIG. 7 is an elevational front view of a focused UVB radiation assemblyfor a phototherapeutic apparatus configured in accordance with a furtherembodiment of the present technology.

FIG. 8 is an exemplary graphical representation of the relativeradiation intensity of a focused UVB radiation assembly with a pulsedxenon UV source configured in accordance with the present technologycompared to the relative radiation intensity of the sun.

DETAILED DESCRIPTION

The present technology is directed to apparatuses, systems, and methodsfor providing focused UVB radiation for vitamin D synthesis. Specificdetails of several embodiments of the technology are described belowwith reference to FIGS. 1A-8. Although many of the embodiments aredescribed below with respect to phototherapeutic systems, devices, andmethods for promoting vitamin D production in the skin, otherapplications (e.g., phototherapeutic treatment of skin diseases) andother embodiments in addition to those described herein are within thescope of the technology. Additionally, several other embodiments of thetechnology can have different configurations, components, or proceduresthan those described herein. A person of ordinary skill in the art,therefore, will accordingly understand that the technology can haveother embodiments with additional elements, or the technology can haveother embodiments without several of the features shown and describedbelow with reference to FIGS. 1A-8.

FIGS. 1A and 1B are isometric views of a phototherapeutic apparatus 100(“apparatus 100”) for focused UVB radiation in an open position and aclosed position, respectively, in accordance with an embodiment of thepresent technology, and FIG. 1C is a top view of the apparatus 100 ofFIGS. 1A and 1B. Referring to FIGS. 1A-1C together, the apparatus 100can include a housing 102 having one or more sidewalls 104 and a door108 that define a chamber or interior space 106 configured toaccommodate a user (e.g., a human patient). The housing 102 can carry aplurality of focused UVB radiation assemblies 110 that direct focusedUVB radiation generally toward the interior space 106 or an irradiationzone in which the user can be exposed to focused UVB radiation. Thefocused UVB radiation assemblies 110 can generate UVB radiation within apredetermined spectrum to promote vitamin D production in human skin.For example, the predetermined spectrum can have a bandwidth of about 8nm focused at about 297 nm (i.e., about 293-301 nm), which is generallyconsidered the peak wavelength for vitamin D synthesis. In otherembodiments, the predetermined spectrum of radiation can have a wider ornarrower bandwidth (e.g., about 6-10 nm) and can be focused around otherwavelengths (e.g., 296 nm, 300 nm, 302 nm, etc.) suitable for vitamin Dproduction. The concentrated UVB radiation provided by the apparatus 100can deliver a large dose of vitamin D (e.g., a weekly dose, a monthlydose, etc.) to the user within a relatively short phototherapy session(e.g., less than 10 minutes, less than 5 minutes, less than 2 minutes,less than 1 minute, etc.) in comparison to the length of sun exposurenecessary to produce the same amount of vitamin D. In other embodiments,the focused UVB radiation assemblies 110 can be focused around other UVBwavelengths that provide therapeutic effects for skin diseases (e.g.,psoriasis) or other disorders (e.g., eczema).

The housing 102 can be sized to allow users (e.g., adult humans) tostand completely within the interior space 106 during a phototherapysession. For example, the user can pivot, slide, and/or otherwise openthe door 108 (e.g., as shown in FIG. 1A) to enter the interior space 106and close the door 108 (e.g., as shown in FIG. 1B) to at least partiallyenclose the user within the housing 102. In various embodiments, thehousing 102 can have a height of approximately 90-100 inches (228.6-254cm) and an outer diameter of approximately 40-50 inches (101.6-127 cm),such as the Maxter V19 ER vertical tanning beds available from ISOItalia USA of Cleveland, Ohio. In other embodiments, the housing 102 canhave other suitable dimensions and/or orientations to accommodate userswithin the interior space 106. For example, the housing 102 can beconfigured horizontally to allow the user to lie down during thephototherapy session. The full-body enclosure provided by the housing102 can expose a large portion of the user's skin to the focused UVBradiation generated in the interior space 106, and therefore promote asubstantial amount of vitamin D production via the user's skin duringthe phototherapy session. In other embodiments, the housing 102 can besmaller and/or configured to accommodate only a portion of the body,such as the face or upper body.

As shown in FIGS. 1A and 1C, a plurality of the focused UVB radiationassemblies 110 can be positioned on or in the sidewall 104 and/or thedoor 108 of the housing 102 behind protective covers or panels 111, anddirected toward the interior space 106 such that the focused UVBradiation assemblies 110 at least partially surround the interior space106. In the illustrated embodiment, the focused UVB radiation assemblies110 are arranged in four columns around the perimeter of the interiorspace 106. In other embodiments, the focused UVB radiation assemblies110 can be arranged in more or fewer columns, or otherwise positioned atleast partially around the interior space 106.

As shown in FIG. 1C, the apparatus 100 can further include one or morecooling fans 118 or other cooling features directed generally toward thefocused UVB radiation assemblies 110 and/or the interior space 106 ofthe housing 102 to at least reduce the operating temperature of the UVBradiation assemblies 110. The fans 118 can also be configured to coolthe UVB radiation assemblies 110 before and/or after operation. Inselected embodiments, the apparatus 100 can be configured to activatethe fans 118 after the UVB radiation assemblies 110 have been turned onto allow the assemblies 110 to quickly ramp up to an operatingtemperature (e.g., a temperature that allows the UVB radiationassemblies 110 to generate UVB radiation) without interference from thefans 118. The duration of the delay between activation of the assemblies110 and fan initiation can be, for example, less than a minute (e.g.,10-15 seconds, 3-5 seconds, etc.). The fan delay can decrease theoverall phototherapy time (e.g., 30 seconds, 2 minutes, 5 minutes, etc.)by decreasing the time it takes for the UVB radiation assemblies 110 tobegin producing focused UVB radiation. In other embodiments, the fans118 can be set at a relatively low intensity and/or speed (e.g., ascompared to typical tanning bed fans) to decrease the interference withthe ramp up time of the UVB radiation assemblies 110. In furtherembodiments, the apparatus 100 can be configured to prevent the userfrom entering the interior space 106 until after the UVB radiationassemblies 110 are at or near their operating temperature such that theramp up time does not increase the overall phototherapy time.

FIG. 1D is an enlarged side view of an individual focused UVB assembly110 configured in accordance with an embodiment of the presenttechnology. The focused UVB assembly 110 can include a UV radiationsource 112 and a filter 116 on or over the UV radiation source 112 thatat least substantially blocks UV radiation outside of a predeterminedspectrum that facilitates vitamin D synthesis. In certain embodiments,for example, the filter 116 can substantially block UV radiation outsideof a predetermined 10 nm spectrum ranging from approximately 292 nm toapproximately 302 nm (i.e., centered at about 297 nm). In otherembodiments, the filter 116 can be configured to block UV radiationoutside of a predetermined spectrum having a wider or narrower bandwidth(e.g., a 5 nm spread, a 6 nm spread, an 8 nm spread, a 20 nm spread)and/or centered around a higher or lower wavelength (e.g., 296 nm, 300nm, 302 nm, etc.).

In selected embodiments, the UV radiation source 112 includes one ormore high intensity discharge (“HID”) lamps, such as a metal-halide lampthat generates light by producing an electric arc through a gaseousmixture between electrodes 113 in an arc tube 115. As described infurther detail below, in certain embodiments, the metal-halide radiationsource 112 can be doped with chemicals to increase the UVB content ofthe energy emitted by the radiation source 112. In other embodiments,the UV radiation source 112 can include other types of HID lamps, lampshaving higher or lower powered bulbs (e.g., 160 W, 200 W, 500 W, 650 W,700 W, 800 W, etc.), and/or other suitable UV radiation sources. Forexample, the radiation source 112 can include a plurality of lightemitting diodes (LEDs) that can emit light at one or more predeterminedwavelengths (e.g., LEDs available from Sensor Electronic Technology,Inc. of Columbus, S.C.), excimer lamps that can emit light within anarrow spectral range (e.g., excimer lamps available from Ushio ofCypress, Calif.), and/or pulsed xenon lamps (e.g., as described infurther detail below with respect to FIG. 7).

In various embodiments, each of the UV radiation sources 112 may havethe same intensity to provide substantially uniform UVB exposure to theuser in the interior chamber 106. In other embodiments, the UV radiationsources 112 can be arranged according to varying degrees of power. Forexample, one or more UV radiation sources 112 with higher powered HIDlamps (e.g., 650-800 W) can be positioned at an upper portion of theapparatus 100 (FIGS. 1A and 1C) proximate the facial region and one ormore lower powered HID lamps (e.g., 500-600 W lamps) can be positionedat the lower portion of the apparatus 100. In other embodiments, the UVradiation sources 112 can be arranged in other suitable configurationsto transmit UV radiation toward the interior space 106 of the apparatus100.

In the embodiment illustrated in FIG. 1D, the filter 116 is a coatedcylindrical tube or sleeve 119 that extends over the length (e.g., 4inches) of the UV radiation source 112 and is offset from the UVradiation source 112 by a plurality of stand-offs 114 at each endportion of the filter 116. The stand-offs 114, for example, can create a1 inch (25.4 mm) space between the UV radiation source 112 and thefilter 116. The sleeve 119 may also provide an insulative enclosure overthe UV radiation source 112 that allows the radiation source 112 to rampup quickly to its operating temperature. In other embodiments, thestand-offs 114 can be longer or shorter, and/or the filter 116 can beseparated from the UV radiation source 112 using other suitable means.In further embodiments, the filter 116 can have other suitable shapesthat cover at least a portion of the UV radiation source 112.

The sleeve 119 can be made from a substrate (e.g., quartz glass,Plexiglas, etc.) coated with UV or other optical filtering materials,such as hafnium dioxide, zinc oxide, cesium, titanium dioxide, and/orvarious other optical filtering materials. One or more coatings can beapplied to the substrate to filter out UV radiation below a lowerthreshold of the predetermined spectrum (e.g., wavelengths below 100 nm,285 nm, 287 nm, 294 nm, etc.), and additional coatings can be applied tothe substrate to filter out UV radiation above an upper threshold of thepredetermined spectrum (e.g., wavelengths above 300 nm, 302 nm, 310 nm,etc.). For example, the filter 116 can include a titanium dioxidecoating to block wavelengths less than 185 nm and prevent ozone fromforming, and can include additional coatings to block other wavelengthsoutside the predetermined spectrum. In other embodiments, the substratecan include a single coating configured to at least substantially blockUV radiation outside of the predetermined spectrum. In furtherembodiments, the substrate itself can serve as an absorption filter toblock at least some energy with wavelengths below a predeterminedspectrum, and an interference coating can be applied to the substrate toblock energy with wavelengths higher than the predetermined spectrum.

The coating(s) can be applied to the sleeve 119 using chemical vapordeposition (CVD), physical vapor deposition (PVD), other depositionprocesses, and/or other suitable filter coating methods. In otherembodiments, one or more coatings can be applied directly onto the UVradiation source 112 to block at least some of the UV radiation as itexits the source 112. In further embodiments, the filter coating(s) canbe applied to other portions of the apparatus 100 between the UVradiation source 112 and the interior chamber 106 of the housing 102.For example, filter coating(s) can be applied to the protective covers111 (FIGS. 1A and 1C) in front of the UVB radiation assemblies 110. Instill further embodiments, the sleeve 119 and/or a portion of the UVradiation source 112 can be doped with filtering materials rather thancoated.

In selected embodiments, the UV radiation source 112 can include afilament that generates radiation at least partially concentrated withinthe predetermined spectrum. For example, mercury-based lamps can have arelatively strong concentration of UVB radiation around 297 nm, and maytherefore be used in conjunction with or in lieu of the filter 116 totransmit focused UVB radiation suitable for vitamin D synthesis. Inother embodiments, the UV radiation source 112 can include othersuitable filaments and/or features that reduce UV radiation outside ofthe predetermined spectrum.

FIGS. 2A and 2B are exemplary graphical representations of the relativespectral powers of the UV radiation source 112 before and after focusingthe UVB radiation with the filter 116. As shown in FIG. 2A, the UVradiation source 112 may generate UV light in a broad spectrum ofwavelengths (e.g., between about 260-400 nm (i.e., visible light)).However, as shown in FIG. 2B, applying the filter 116 (e.g., the coatedor doped sleeve 119, a coating on the UV radiation source 112, etc.) tothe UV radiation source 112 can at least substantially block UVradiation less than approximately 290 nm and greater than approximately310 nm. The filter 116 can, therefore, concentrate the UV radiationemitted by the UV radiation source 112 around the wavelengths associatedwith vitamin D production (e.g., 297 nm, 300 nm, 302 nm, etc.), andthereby provide sufficient UVB radiation to initiate high levels ofvitamin D production (e.g., about 40,000 IU, about 70,000 IU, about100,000 IU, etc.) within a relatively short period of time (e.g., lessthan 1 minute, less than 5 minutes, etc.).

During a phototherapy session, the apparatus 100 can expose the user tofocused UVB radiation within a predetermined radiation spectrum todeliver a dose of vitamin D within a relatively short exposure time. Inone embodiment, for example, the apparatus 100 can provide a dose ofvitamin D in less than two minutes. The dose of vitamin D can beequivalent to the user's required weekly dose of vitamin D. For example,if the user requires a daily vitamin D dose of approximately 10,000 IUfrom sunlight, the apparatus 100 can deliver approximately 70,000 IUduring the phototherapy session. In other embodiments, the apparatus 100can be configured to provide larger or smaller daily vitamin D doses(e.g., 6,000 IU/day, 20,000 IU/day, etc.), and/or the vitamin D dose cancorrespond to vitamin D requirements for longer or shorter periods oftime (e.g., a two day dose, a two week dose, a monthly dose, etc.).

The amount of vitamin D in the vitamin D dose can vary depending onuser-specific characteristics, such as skin type (e.g., as determined bythe Fitzpatrick scale or modifications thereof), age, weight, averagesun exposure, and/or other parameters that may affect the vitamin Dsynthesis and needs. For example, users with lighter skin tonestypically require a shorter UVB exposure times and/or lesser UVBintensities to receive a sufficient vitamin D dose than users withdarker skin tones. Older users produce less vitamin D from the sameamount of exposure to UVB as younger users, and therefore typicallyrequire longer exposure times and/or greater UVB intensity than youngerusers. The apparatus 100 can therefore be configured to provide varyinglevels of vitamin D by adjusting the duration of the phototherapysession and/or intensity of the focused UVB radiation. In otherembodiments, the apparatus 100 does not adjust for user-specificcharacteristics, and performs a standardized phototherapy session on allusers. Without being bound by theory, it is thought that the human bodywill inherently prevent toxic levels of vitamin D from being produced inthe skin when the user is exposed to higher than necessary UVBradiation. Therefore, the apparatus 100 is at least less likely toproduce toxic levels of vitamin D than vitamin D taken in the form ofdietary supplements, which bypass the body's built-in protection.

The apparatus 100 can be adjusted for variations in the vitamin D doseusing a local controller 121 (FIGS. 1A and 1B; shown schematically)and/or remote server coupled thereto via a communications link (e.g.,the Internet, an intranet, etc.) based on various operationalparameters. For example, the controller 121 can increase the vitamin Ddose provided during a phototherapy session by increasing the length ofthe phototherapy session (i.e., the exposure time) because the userreceives more UVB radiation during longer exposure times. The vitamin Ddose can also be increased by increasing the concentration of filteredUVB rays associated with vitamin D synthesis (e.g., via the filter 116).In selected embodiments, the apparatus 100 can emit concentrated levelsof UVB radiation that provide users with weekly doses of vitamin Dwithin short exposure times, such as less than 5 minutes, 3 minutes, 2minutes, 1 minute, 30 seconds, etc.

In various embodiments, the apparatus 100 can be configured to limit thevitamin D dose based on a minimum erythemal dose (“MED”), which is thethreshold dose of UVB radiation that produces erythema (i.e., visiblereddening of the skin 24 hours after exposure). The MED depends on theuser's skin type, but the measurement has been standardized (usingunprotected, untanned skin type 2 on the Fitzpatrick skin type scale) tocompare and control UVB exposure in tanning beds. For example, certainregulations prohibit tanning beds from exceeding 4 standardized MEDs perexposure. As such, the apparatus 100 can also be configured to limitphototherapy sessions to 4 standardized MEDs. In other embodiments, theapparatus 100 can limit phototherapy sessions to less than 4standardized MEDs, while still providing users with relatively highvitamin D doses because the narrow bandwidth of radiation generated bythe UVB radiation assemblies 110 limit the user's UVB exposure to thefocused spectrum of UVB radiation associated with vitamin D synthesis.In one embodiment, for example, the apparatus 100 can limit phototherapysessions to approximately 1 standardized MED. In other embodiments, theapparatus 100 can adjust the phototherapy session based on the MEDassociated with the user's skin type (e.g., 75% of the user's MED, 50%of the user's MED, etc.). Accordingly, the apparatus 100 can at leastreduce the likelihood of skin redness resulting from UVB exposure, whilestill providing sufficient levels of focused UVB radiation to inducevitamin D production during the phototherapy session. Therefore, theapparatus 100 can be configured to inhibit the negative effects (e.g.,sunburn and skin cancer) typically associated with tanning beds and/orexcessive sun exposure.

As further shown in FIGS. 1A and 1B, the apparatus 100 can also includea user interface 120 that allows the apparatus 100 to operationallyinterface with individuals receiving phototherapy (e.g., the users)and/or individuals administering the phototherapy (e.g., physicians ortrained technicians) via visual and/or audible signals (e.g., textualinstructions, audible commands, animations, etc.). For example, the userinterface 120 can include a touch screen, display screen, keyboard,mouse, card swipe, PIN pad, and/or other suitable devices that canreceive information and/or otherwise communicate with users. In theillustrated embodiment, the user interface 120 is positioned on theexterior of the housing 102. However, in other embodiments, the userinterface 120 can be positioned elsewhere on the apparatus 100 (e.g.,within the interior space 106), or can be remotely coupled to theapparatus 100 (e.g., via the Internet, a secured intranet, and/or othersuitable connection).

The user interface 120 can provide instructions to the user related tothe apparatus 100 and/or query the user regarding various user-specificcharacteristics that may affect the parameters of the UVB exposureprovided by the apparatus 100. For example, the user interface 120 caninstruct or prompt the user to answer questions related to his or herskin type (e.g., using a Fitzpatrick skin test and/or modificationsthereof), and the apparatus 100 can use the answers to identify theuser's skin type (e.g., via a controller or a remote computercommunicatively coupled to the apparatus 100). The user interface 120can also be configured to receive information related to the user's age,weight, recent sun exposure, diet, and/or other suitable factors thatmay affect the user's vitamin D needs. This user-specific informationcan be used to derive parameters for a phototherapy session, such asexposure time.

In selected embodiments, the user interface 120 can also be configuredto receive feedback related to previous phototherapy sessions. Forexample, the user can indicate whether he or she experienced any rednesscaused by a previous phototherapy session (i.e., the phototherapysession exceeded the user's MED), and the apparatus 100 can adjust theparameters of subsequent phototherapy sessions to reduce or preventfuture redness.

The user interface 120 can also be configured to create user accountsthat associate users with phototherapy sessions performed by theapparatus 100 and/or other phototherapeutic apparatuses communicativelylinked to the apparatus 100 in the same network. FIGS. 3A-3C, forexample, illustrate display pages 350 a-c, respectively, on the userinterface 120 that can be used to register and log into a user account.In other embodiments, the display pages 350 a-c can be displayed onother portions of the apparatus 100 (e.g., an additional display) and/orremote devices communicatively coupled thereto, such as a home computeror mobile phone communicatively coupled to the apparatus 100 via theInternet or other suitable communications link.

Referring first to FIG. 3A, the display page 350 a can include variousbuttons or icons that allow the user to enter user identificationinformation to register or create a user account. In the illustratedembodiment, the display page 350 a includes a box 352 that requests theuser to enter his or her phone number using a key pad 354 displayed onthe display page 350 a. The display page 350 a also includes a “delete”button 356 to edit the numbers entered in the box 352 and buttons tonavigate between display pages, such as a “back” button 358 to return tothe previous page, a “main” button 360 to return to a home page, and/orother suitable buttons. In other embodiments, the display page 350 a canbe configured to receive other forms of user identification informationto create the user account, including an email address and credit cardinformation (e.g., entered via a card swipe).

Once the user has entered his or her identification information, theuser can select a “next” button 362 to navigate to display page 350 billustrated in FIG. 3B. The display page 350 b allows a user to log intohis or her user account. A new user can scan his or her fingerprint viaa fingerprint scan box 364 on the display page 364 during the initialregistration phase, and the apparatus 100 can store this informationlocally or remotely on a database to allow the user to log into his orher user account during subsequent phototherapy sessions via fingerprintidentification. In other embodiments, the fingerprint scan can beperformed by a device positioned elsewhere on the apparatus 100. If theuser does not wish to log in using his or her fingerprint, the user canselect a “manual login” button 366 to manually access the user's accountby typing in a user name, password, and/or other information thatassociates the user with his or her user account. In furtherembodiments, the user interface 120 can include facial recognitionsoftware that allows the apparatus 100 to recognize the user by scanninghis or her face. This facial recognition scan may also be configured toallow the user interface 120 to determine the user's skin type andadjust the parameters of the phototherapy session accordingly. In stillfurther embodiments, the user interface 120 and/or other portion of theapparatus 100 can include other suitable forms of biometric recognitionto identify users.

Once the user has logged into his or her account, the user interface 120can navigate to display page 350 c shown in FIG. 3C that can serve asthe user's home page. The display page 350 c can include a plurality ofselection buttons 368 that navigate the user interface 120 to variousother display pages. For example, selecting a “timer control” button 368can navigate the user interface 120 to a display page that allows theuser to select or enter the duration of his or her phototherapy session.The user can select the “your account” button 368 to view and/or editinformation related to his or her user account (e.g., the user'saddress, medical history, credit card associated with the user account,etc.), and the user can select the “settings” button 368 to navigate theuser interface 120 to a display page where the user can view and/or editsettings associated with the apparatus 100, user preferences, and/orother user-specific settings (e.g., skin type, age, etc.). In variousembodiments, the user can select the “settings” button 368 and/or otherbuttons on the display page 350 c to enter feedback related to previousphototherapy sessions, and the apparatus 100 can modify subsequentphototherapy sessions accordingly. The “reports” button 368 can beselected to illustrate data related to the user's previous phototherapysessions. For example, previous doses of vitamin D can be displayed forthe user in the form of charts and/or graphs. The “reports” button 368can also be configured to display other types of summaries related tothe user and previous phototherapy sessions. In various embodiments, theuser can select the “shop” button 368 to purchase a package ofphototherapy sessions (e.g., on a per minute and/or per session basis)and/or related products. The “info” button 368 can be selected to showinformation related to the apparatus 100 in general (e.g., technicalspecifications), vitamin D-related information (e.g., daily doserecommendations, effects of vitamin D deficiency, articles related tovitamin D, etc.), and/or other suitable information. The “info” buttoncan also be used to access online resources (e.g., medical journals)when the apparatus 100 is connected to the Internet and/or a securedintranet. When the apparatus 100 is connected to the Internet or anintranet, the selection buttons 368 can be used to access onlineresources (e.g., medical journals).

As further shown in FIG. 3C, the display page 350 c can also include anactivation button 370 (labeled “use Dshot”) that allows the user tobegin a phototherapy session. In various embodiments, the activationbutton 370 may navigate the display page 350 c to a display thatrequests the user to add information that may affect the parameters ofthe phototherapy session. In another embodiment, the activation button370 may begin a countdown to the beginning of the phototherapy session.This embodiment can accommodate for the ramp up time of the UVBradiation source 112 and/or other features of the apparatus 100.Additionally, as shown in FIG. 3C, the display page 350 c can include an“exit” button 372 at any time to log out of his or her user account.

FIG. 4 is a block diagram illustrating a method 400 of generatingfocused UVB radiation for vitamin D synthesis in accordance with anembodiment of the present technology. In various embodiments, the method400 can be performed by a phototherapeutic apparatus including featuresgenerally similar to the features of the apparatus 100 described abovewith reference to FIGS. 1A-3C. The method 400 can optionally includereceiving user-specific information before a vitamin D phototherapysession (block 410). The user-specific information may include skin type(e.g., as characterized by the Fitzpatrick scale), age, weight, currentvitamin D level, feedback related to previous vitamin D phototherapysessions, and/or other information that may affect the user's vitamin Ddose and/or operating parameters of the phototherapeutic apparatus. Inselected embodiments, the person undergoing the vitamin D phototherapy(i.e., the user) can enter his or her user-specific information via auser interface and/or other suitable device communicatively coupled tothe phototherapeutic apparatus (e.g., via a website and/or a smart phoneapplication). In other embodiments, the individual administering thephototherapy session (e.g., a physician, a nurse, etc.) can input theuser-specific information via a user interface, a remote computercommunicatively coupled to the phototherapeutic apparatus, and/or othersuitable input devices. This embodiment allows the phototherapy to becontrolled by a professional and avoids improper use by an untraineduser.

The method 400 can continue by determining performance parameters of thephototherapy session via a local controller and/or a remote servercoupled thereto (block 420). For example, an algorithm can use theuser-specific information to determine the appropriate vitamin D doseprovided by the apparatus, the duration of the phototherapy session,and/or the intensity of focused UVB exposure for the phototherapysession. In other embodiments, the user can select operationalparameters of the phototherapy session (e.g., exposure time) withoutentering user-specific information, and/or override the recommendedparameters provided by the algorithm. In further embodiments, the methodcan bypass block 420, and use non-user specific exposure parameters forthe phototherapy session. In one embodiment, for example, eachphototherapy session can deliver approximately 50,000 IU of vitamin D toa typical user within less than a minute of focused UVB exposure. Inother embodiments, the parameters of the phototherapy session maydiffer.

As further shown in FIG. 4, the method 400 can include generatingfocused UVB rays within a predetermined spectrum (block 430). Forexample, a filter and/or a suitable UV radiation source can emit UVBradiation within a narrow bandwidth (e.g., a bandwidth of about 6-10 nm)generally centered at a wavelength (e.g., 297 nm, 302 nm, etc.) thatfacilitates efficient vitamin D production through the skin. In oneembodiment, the predetermined spectrum ranges from approximately 290 nmto approximately 310 nm. In other embodiments, the predeterminedspectrum can be broader or narrower.

Filtering and/or otherwise generating the focused UVB rays can deliver adose of vitamin D to the user in a relatively short amount of time(block 440). For example, the method 400 can deliver a weekly dose ofvitamin D (e.g., 700,000 IU) within 2 minutes. The vitamin D doseprovided by the apparatus can be approximated by the previously provideduser-specific characteristics and the operating parameters of theapparatus. To obtain different vitamin D doses, for example, the method400 can include increasing the intensity of the UVB rays within thepredetermined spectrum and/or focusing the predetermined spectrum moreclosely toward the wavelength associated with vitamin D synthesis. Theexposure time can also be adjusted to change the vitamin D dose. Infurther embodiments, the method 400 can also include adjusting theparameters of the phototherapy session to limit the MED the user isexposed to and/or other suitable steps associated with providing vitaminD phototherapy.

FIG. 5A is an isometric view of a phototherapeutic apparatus 500(“apparatus 500”) for focused UVB radiation configured in accordancewith another embodiment of the present technology. The apparatus 500includes several features generally similar to the features of theapparatus described above with respect to FIGS. 1A-1D. For example, theapparatus includes a plurality of focused UVB radiation fixtures orassemblies 510 a (“radiation assemblies 510 a”) that emit energy withina predetermined wavelength spectrum (e.g., about 293-301 nm, 298-306 nm,etc.). In the illustrated embodiment, the radiation assemblies 510 a arecarried by two housings, arms or columns (identified individually as afirst column 530 a and a second column 530 b, and referred tocollectively as columns 530) that are mounted on or otherwise attachedto a pedestal or base 532, and the radiation assemblies 510 a aredirected generally inward toward a central portion 534 of the base 532.The base 532 and the columns 530 together define an irradiation zone inwhich a human patient can be exposed to focused UVB energy emitted bythe radiation assemblies 510 a. When a user (e.g., a human patient)stands on or is otherwise positioned at the central portion 534 of thebase 532, the radiation assemblies 510 a can irradiate the user's skinto stimulate vitamin D production in the skin during a phototherapysession. In various embodiments, the central portion 534 of the base 532and/or the columns 530 may rotate relative to each other (e.g., thecolumns 530 may rotate around the central portion 534) to expose allsides of the user's body to the energy emitted by the radiationassemblies 510 a.

In the embodiment illustrated in FIG. 5A, the apparatus 500 includeseight radiation assemblies 510 a in each column 530 that emit energy atsubstantially similar wavelengths and similar intensities. In certainembodiments, the radiation assemblies 510 a in the first column 530 acan be vertically offset from the radiation assemblies 510 a in thesecond column 530 b to prevent the irradiation from radiation assemblies510 a of the first column 530 a from directly overlapping theirradiation from the radiation assemblies 510 a of the second column 530b. For example, the radiation assemblies 510 a in the first column 530 acan be offset from radiation assemblies 510 a in the second column 510ab by about one radius of an individual radiation assembly 510 a. Thisstaggering of the radiation assemblies 510 a can provide a more uniformintensity of irradiation along the length of the columns 530 and preventcertain areas of a user's skin from being exposed to more irradiationthan others. In other embodiments, the apparatus 500 can include columns530 with fewer than or more than eight radiation assemblies 510 a, asingle column 530 of radiation assemblies 510 a, more than two columns530 of radiation assemblies 510 a (e.g., four columns, six columns,etc.), and/or the radiation assemblies 510 a can be arranged in othersuitable configurations. For example, the radiation assemblies 510 a canbe carried by a housing (e.g., the housing 102 of FIGS. 1A-1C) anddirected generally inward toward an enclosed space defined by thehousing.

Similar to the apparatus 500 discussed above with reference to FIGS.1A-1D, the apparatus 500 of FIG. 5A can emit high intensity focused UVBradiation to facilitate vitamin D production in the skin duringrelatively short phototherapy sessions. For example, the apparatus 500can provide a sufficient amount of irradiation during a one-minutephototherapy session to stimulate the production of a weekly or monthlydose of vitamin D. The exposure time of each phototherapy session can beselected based on the on the user's skin type (e.g., as defined by theFitzpatrick scale) and the intensity of the radiation assemblies 510 a.For example, the lighter the user's skin tone, the less exposure timenecessary to obtain the desired level of vitamin D synthesis in theuser's skin. As another example, the higher the intensity of theirradiation provided by the apparatus 500, the less exposure timenecessary to obtain the desired irradiation for vitamin D production. Invarious embodiments, the duration of the phototherapy sessions can alsobe selected to at least reduce the likelihood that users experiencesunburn after the phototherapy session. For example, the exposure timeto UVB irradiation can be limited to a user-specific MED of 1.0 or less(e.g., an MED of 0.75). In other embodiments, the exposure time ofapparatus 500 can be determined using other suitable parameters for UVBirradiation and/or vitamin D synthesis.

As shown in FIG. 5A, each radiation assembly 510 a can include aradiation source 512, a reflector 536 partially surrounding theradiation source 512, and an optical filter 538 forward of the radiationsource 512. FIG. 5B is an enlarged partially schematic side view of aradiation assembly 510 a of FIG. 5A configured in accordance with anembodiment of the present technology. As shown in FIG. 5B, the radiationsource 512 can emit energy (e.g., UV light; as indicated by the solidlines), and at least some of the energy can contact the reflector 536(e.g., a mirrored substrate or coating) before exiting the radiationassembly 510 a. The reflector 536 can divert or otherwise direct thelight forward (e.g., as indicated by the solid lines) toward the filter538 where light within a predetermined bandwidth (e.g., about 292-302nm) can exit the radiation assembly 510 a (e.g., as indicated by thebroken lines). In the illustrated embodiment, the reflector 536 iscurved around the radiation source 512 such that the light emitted bythe radiation source 512 collaminates upon contact with the reflector536. The collaminated beam of light can then travel forward toward thefilter 538, and pass through the filter 538 at the same angle ofincidence (e.g., 0°) to provide substantially uniform filtering of thelight.

In the embodiment illustrated in FIG. 5B, the radiation source 512 is ametal-halide lamp, which is a type of HID gas discharge lamp thatgenerates light by producing an electric arc through a gaseous mixturebetween two electrodes 513 in an arc tube or envelope 515. The arclength (i.e., about the distance between the electrodes 513) of themetal-halide lamp can be relatively small with respect to radiationassembly 510 a as a whole such that the metal-halide lamp acts similarto a point source to facilitate collamination of the light. In certainembodiments, for example, the electrodes 513 can be spaced apart fromeach other such that the metal-halide lamp has an arc length of about10-12 mm (e.g., about 11 mm, about 11.5 mm, etc.). In other embodiments,the metal-halide lamp can have larger or smaller arc lengths dependingon the configuration of the metal-halide lamp and the sizing of theother components of the radiation assembly 510 a (e.g., the reflector536). Metal-halide lamps typically have a ramp up period to warm up toan operating temperature. Therefore, in certain embodiments, theradiation assembly 510 a can include shutters or other covers (notshown) that temporarily enclose or insulate the radiation source 512 fora time period (e.g., about 2 minutes, about 1 minute, etc.) to allow themetal-halide lamp to quickly ramp up to its operating temperature.

In various embodiments, the gas mixture in the arc tube 515 can beselected to increase the UVB content of the emissions of themetal-halide lamp. For example, the gas mixture can be doped to generateabout 6% of the total emissions in the UVB range (e.g., about 280-315nm) in comparison to normal tanning bed lamps that have about 1% oftheir emissions in the UVB range. Suitable gas mixtures for increasedUVB content are available from Heraeus Nobelight of Plainview, N.Y. Theincreased UVB content of the emissions can increase the intensity of theUVB emitted by the radiation assembly 510 a, and therefore may decreasethe overall exposure time necessary to achieve a desired vitamin D dose.

As shown in FIG. 5B, the radiation assembly 510 a can further include anoptional cover or shield 540 between the radiation source 512 and thefilter 538 to at least substantially prevent light from exiting theradiation assembly 510 a without first propagating off of the reflector538. In the illustrated embodiment, for example, the shield 540 is atubular body spaced apart from the radiation source 512 (e.g., usingstand-offs similar to the stand-offs 114 of FIG. 1D) and positionedaround a portion of the radiation source 512 forward of the arc tube515. The shield 540 can block light that propagates forward from the arctube 513 such that the light first contacts the reflector 538 beforeexiting the radiation assembly 510 a. In this manner, the shield 540 canpromote collamination of light by the reflector 536 before the lightcontacts the filter 538. In other embodiments, the shield 540 can haveother suitable shapes or configurations that prevent light frompropagating directly forward through the filter 538.

The filter 538 can be a narrow pass filter that prevents UVB radiationoutside of a predetermined bandwidth from passing through the filter538. For example, the filter 538 can at least substantially block UVBradiation outside of a 10 nm spectrum centered at about 297 nm (i.e.,about 292-302 nm). In other embodiments, the filter 538 can at leastsubstantially block UVB radiation outside of a narrower bandwidth (e.g.,a 6 nm spectrum, an 8 nm spectrum, etc.), a wider bandwidth (e.g., a 12nm spectrum), and/or the spectrum can be centered around anothersuitable UVB wavelength (e.g., 298 nm, 300 nm, 302 nm, etc.).

As shown in FIG. 5B, the filter 538 can include a substrate 542 (e.g.,glass, plastic, etc.) and at least one interference coating 544 appliedto the substrate 542. For example, the coating 544 can be sprayed ontothe substrate 542 and/or otherwise disposed on the substrate 542 usingmethods known to those skilled in the art. In certain embodiments, thesubstrate 542 can be made from a material (e.g., glass) that blocks atleast some of the UV light emitted by the radiation source 512. Forexample, the substrate 542 can be made from an absorption glass thatblocks UV radiation below, for example, about 290 nm. The coating 544(e.g., one or more optical coatings) can be applied to the substrate 542to provide additional filtering of energy outside of the predeterminedbandwidth. For example, the coating 544 may provide a higher degree ofprecision in filtering the energy outside of a predetermined spectrumthan provided by the substrate 542 such that the substrate 542 and thecoating 544 together form a narrow pass filter. In certain embodiments,for example, a first coating can be applied to the substrate 542 toblock light with wavelengths less than the minimum wavelength of thepredetermined spectrum, and a second coating can be applied to thesubstrate 542 to block light with wavelengths higher than the maximumwavelength of the predetermined spectrum. In other embodiments, thesubstrate 542 or the coating 544 can alone provide suitable filtering oflight outside of the predetermined spectrum. Substrates 542 and coatings544 that provide at least some filtering of UV radiation outside of apredetermined spectrum are available from Schott of Elmsford, N.Y.

In various embodiments, other portions of the radiation assembly 510 acan include an interference coating that blocks at least some radiationoutside of the desired wavelength spectrum. For example, an outer bulb517 of the metal-halide lamp can include an interference coating thatblocks at least some UV radiation outside the UVB spectrum from exitingthe metal-halide lamp. A coating, for example, can be applied to theouter bulb 517 to block some of the emissions in the UVC range (e.g.,about 100-280 nm) and inhibit ozone from forming. In this embodiment,the radiation source 512 narrows the spectrum of light exposed to thefilter 538, and therefore the filter 538 need only be concerned withfurther narrowing the bandwidth of light permitted to pass through thefilter 538.

FIG. 5C is an enlarged partially schematic side view of a focused UVBradiation assembly 510 b (“radiation assembly 510 b”) configured inaccordance with another embodiment of the present technology. Theradiation assembly 510 b can include features generally similar to thefeatures of the radiation assembly 500 a described above with respect toFIG. 5B. For example, the radiation assembly 510 b includes the UVradiation source 512, the reflector 536 at least partially surroundingthe radiation source 512, the filter 538, and the shield 540 between theradiation source 512 and the filter 538. The radiation source 512 can bea metal-halide lamp that functions substantially as a point sourcerelative to the radiation assembly 510 b, and emits energy radiallyoutward (e.g., as indicated by the solid lines of FIG. 5C). The shield540 can deflect or otherwise redirect energy emitted from the radiationsource 512 back toward the reflector 536 such that the reflector 536 canat least substantially collaminate the light before it passes throughthe filter 538. In the embodiment illustrated in FIG. 5C, the shield 540has a substantially hemispherical shape and is connected to a baseportion 546 of the metal-halide lamp with a stand-off 548 (e.g., a rod,a bar, etc.) that extends from the base portion 546 to the shield 540.In other embodiments, the shield 540 can have other suitableconfigurations to block energy from exiting the radiation assembly 510 bwithout first contacting the collaminating reflector 536.

FIG. 6 is an exemplary graphical representation of the relativeradiation intensity of a focused UVB radiation assembly with ametal-halide UV source (e.g., the radiation assemblies 510 a and 510 bdescribed above with respect to FIGS. 5A-5C) compared to the relativeradiation intensity of the sun. More specifically, curve 601 (shown as abroken line) represents the intensity of the metal-halide radiationassembly, curve 603 (shown as a solid line) represents the intensity ofthe sun measured at about noon during the summer in Melbourne,Australia, and curve 605 represents the action spectrum of UV radiationknown to promote vitamin D production in the skin. As illustrated inFIG. 6, the metal-halide radiation assembly emits UV light primarilybetween about 292-302 nm (e.g., focused at about 297 nm), and thereforemost of the emissions are within the action spectrum 605 for vitamin Dproduction. In contrast, despite being measured at one of the sun's peakenergy times and locations, solar energy has a relatively low intensityof UV light within the UVB spectrum (i.e., about 280-315 nm), and has arelatively high intensity of UV light in the UVA spectrum (i.e., about315-400 nm). For example, 99.7% of the UV emissions from themetal-halide radiation assembly can be within the focused UVB range,whereas only about 3.4% of the solar emissions are within the focusedUVB range. Accordingly, phototherapeutic apparatuses that include themetal-halide radiation assemblies depicted in FIG. 6 can emit UV energywith a much higher UVB content and intensity than normal sun exposure.This concentrated UVB radiation can be used to promote vitamin Dproduction in the skin, and do so in a much shorter exposure time thancan be provided by the sun. For example, in certain embodiments, the UVBirradiation that is provided by about 38 minutes of sun exposure (atpeak times) can be provided by less than a minute (e.g., 58 seconds) ofexposure to the metal-halide radiation assembly. In addition, the highintensity of the UVB radiation provided by the metal-halide radiationassembly can facilitate significantly more vitamin D synthesis in theskin than the lower intensity UVB radiation provided by the sun. Incertain embodiments, for example, the metal-halide radiation assemblycan provide at least three times the production of vitamin D in the skinthan can be obtained from the sun (e.g., 74,500 IU via focused UVBradiation compared to 20,000 IU equivalent via solar energy). Moreover,despite the high concentration of UVB radiation, the focused UVBradiation assembly exposes a subject (e.g., a human patient) to lessoverall UV energy during a phototherapy session than sun exposure (e.g.,62 times less UV energy than the sun) because much of the UV radiationoutside the predetermined spectrum is filtered out by the focused UVBradiation assembly (e.g., via the filter 538 of FIGS. 5A-5C).Accordingly, the focused UVB radiation assembly provides a substantiallymore efficient means for producing vitamin D in the skin than the sun,and does so without the geographic and weather-dependent initiations ofsun exposure.

FIG. 7 is a front elevational view of a focused UVB radiation assembly710 (“radiation assembly 710”) for a phototherapeutic apparatusconfigured in accordance with a further embodiment of the presenttechnology. The radiation assembly 710 can include several featuresgenerally similar to the features of the radiation assemblies 110, 510 aand 510 b described above with respect to FIGS. 1D, 5B and 5C. Forexample, the radiation assembly 710 can include a UV radiation source712, a reflector 736 positioned behind and partially around theradiation source 712, and a filter 738 forward of the radiation source712. In the illustrated embodiment, radiation source 712 is a xenon lamp750, which produces a pulsed or continuous beam of light 752 in a tubeby passing electricity through ionionized xenon gas at high pressure.The xenon lamp 750 can be coupled to a power source (e.g., a 16 kW powersource; not shown), and forced air can be supplied from one or both endsof the radiation assembly 710 for cooling. Xenon lamps inherently emitenergy with a high UVB content, and therefore facilitate the focused UVBirradiation provided by the radiation assembly 710. Suitable xenon lamps(e.g., pulsed linear xenon lamps) for the radiation assembly 710 areavailable from Heraeus Nobelight GmbH of Hanau, Germany.

As shown in FIG. 7, the xenon lamp 750 can be an elongated structurethat emits a linear beam of UV light 752. For example, the xenon lamp750 can have a diameter of about 8 mm and a length of about 165 mm suchthat can extend along the height or length of a phototherapeuticapparatus (e.g., the phototherapeutic apparatuses 100 and 500 of FIGS.1A and 5A). In other embodiments, the xenon lamp can be longer orshorter length and/or have smaller or larger diameters. The reflector736 (e.g., a barrel reflector) can also be an elongated structure thatextends along the length of the xenon lamp 750 to direct light forwardtoward the filter 738 where filtered UVB light exits the radiationassembly. The filter 738 can include an absorption glass or other typeof substrate that blocks energy below a certain wavelength (e.g., belowabout 290 nm) and an interference coating can block energy with higherwavelengths (e.g., above about 306 nm).

The radiation assembly 710 with the xenon lamp 750 can be used inconjunction with or in lieu of the metal-halide lamps in thephototherapeutic apparatuses 100 and 500 described above. For example,the radiation assembly 710 can be carried by a column (e.g., one of thecolumns 530 of the phototherapeutic apparatus of FIG. 5A), and the xenonlamp 750 can be configured to generate a beam of light that extendssubstantially along the length of the column. During operation, one ormore of the radiation assemblies 710 can be rotated around a base (e.g.,the central portion 534 of the base 532 of FIG. 5A) to provide focusedUVB radiation to a subject (e.g., a human patient) standing on the base.In other embodiments, one or more radiation assemblies 710 can beincorporated into a housing (e.g., the housing 102 of FIG. 1A) andconfigured to direct emissions toward an enclosed space provided by thehousing.

FIG. 8 is an exemplary graphical representation of the relativeradiation intensity of a focused UVB radiation assembly with a pulsedxenon UV source (e.g., the radiation assembly 710 of FIG. 7) compared tothe relative radiation intensity of the sun. Curve 801 (shown as abroken line) represents the intensity of the xenon lamp radiationassembly, curve 803 (shown as a solid line) represents solar intensity(measured at about noon during the summer in Melbourne, Australia), andcurve 805 represents the action spectrum for vitamin D production in theskin. As shown in FIG. 8, the solar spectrum (as defined by the areaunder the curve 803) has very little output (e.g., about 3.4%) withinvitamin D action spectrum 805. In contrast, almost all of the output(e.g., over 98%) of the xenon lamp radiation assembly is within thevitamin D action spectrum 805. In addition, the intensity of UVBradiation provided by the xenon lamp radiation assembly is much higherthan that provided by solar energy. Accordingly, the xenon lampradiation assembly can provide focused UVB radiation within the vitaminD action spectrum 805 that facilitates vitamin D synthesis in the skinin significantly shorter exposure times than can be provided by solarenergy. For example, the UVB radiation provided by one xenon lampradiation assembly in less than one minute (e.g., 57 seconds) isequivalent to over 30 minutes (e.g., 38 minutes) of sun exposure.

In various embodiments, the phototherapeutic apparatuses 100 and 500described above can include other types of UV radiation sources (e.g.,radiation sources 112, 512 and 712 of FIGS. 1D, 5B, 5C and 7) that, incombination with optional filters, can provide focused UVB irradiationwithin a predetermined spectrum. For example, the UV radiation sourcecan be comprised of a plurality of LEDs (e.g., thousands of LEDs) thatemit light at a particular wavelength (e.g., 295 nm, 297 nm, 300 nm,etc.). Suitable LEDs are available from, for example, Sensor ElectronicTechnology, Inc. of Columbus, S.C. In certain embodiments, one or moreLEDs can be arranged in individual radiation assemblies (e.g., similarto the metal-halide lamps of FIGS. 5A-5C). In other embodiments, theLEDs can be arranged in elongated rows and/or columns extending alongthe length of the phototherapeutic apparatus (e.g., similar to the xenonlamp of FIG. 7). The substantially monochromatic output of the LEDs maylimit the amount of filtering necessary to provide UVB radiation withina predetermined spectrum. In addition, LEDs have relatively low powerconsumption (e.g., in comparison to HID lamps), and therefore inherentlyprovide power savings. In further embodiments, the UV radiation sourcecan be comprised of excimer lamps that can emit light within a narrowspectral range (e.g., the excimer lamps available from Ushio of Cypress,Calif.) and/or other suitable UV radiation sources that can bemanipulated for focused UVB radiation.

From the foregoing, it will be appreciated that specific embodiments ofthe technology have been described herein for purposes of illustration,but that various modifications may be made without deviating from thedisclosure. For example, various embodiments disclosed herein includefilters that focus UVB radiation around 297 nm. However, in otherembodiments, the filters can focus UVB radiation around otherwavelengths that enable vitamin D production in the skin and/or providetherapeutic effects for other diseases or disorders treated via the skin(e.g., psoriasis, eczema, etc.). Certain aspects of the new technologydescribed in the context of particular embodiments may be combined oreliminated in other embodiments. For example, the metal-halide UV sourcedescribed in FIGS. 5A-5C and/or the xenon UV source described in FIG. 7can be used in lieu of or in conjunction with the UV radiation sourcefor the phototherapeutic apparatus of FIGS. 1A-1C. Additionally,although advantages associated with certain embodiments of the newtechnology have been described in the context of those embodiments,other embodiments may also exhibit such advantages and not allembodiments need necessarily exhibit such advantages to fall within thescope of the technology. Accordingly, the disclosure and associatedtechnology can encompass other embodiments not expressly shown ordescribed herein.

I/We claim:
 1. A phototherapeutic apparatus, comprising: an ultraviolet(UV) radiation assembly comprising: a UV radiation source carried by ahousing; and a reflector positioned forward of the UV radiation sourceto direct the UV energy emitted by the UV radiation source forwardtoward an irradiation zone, the UV energy contacting the reflectorforward of the UV radiation source, wherein the UV radiation assembly isconfigured to emit UV radiation having wavelengths between 290 nm and310 nm to stimulate vitamin D production in skin; and a controllercommunicatively coupled to the UV radiation assembly and configured tocause the phototherapeutic apparatus to limit UV radiation of thephototherapeutic apparatus to less than a user-specific minimumerythemal dose (“MED”) based on a skin tone associated with a user inthe irradiation zone by adjusting a duration of an exposure period. 2.The phototherapeutic apparatus of claim 1 wherein the UV radiationsource comprises a light emitting diode (LED).
 3. The phototherapeuticapparatus of claim 1, further comprising a housing carrying the UVradiation source, wherein: the UV radiation source comprises a pluralityof LEDs arranged in a plurality of columns across the housing; and thereflector comprises a plurality of reflectors corresponding to theplurality of LEDs, the plurality of reflectors positioned forward of thecorresponding plurality of LEDs, wherein the plurality of reflectors areconfigured to direct UV energy emitted by the corresponding LEDs forwardtoward the irradiation zone, the UV energy contacting the plurality ofreflectors forward of the plurality of LEDs.
 4. The phototherapeuticapparatus of claim 1 wherein the UV radiation assembly further comprisesa filter positioned forward of the UV radiation source.
 5. Thephototherapeutic apparatus of claim 1 wherein: the UV radiation sourcecomprises a plurality of UV radiation sources; and the UV radiationassembly further comprises a plurality of filters corresponding to theplurality of UV radiation sources, the plurality of filters positionedforward of the corresponding UV radiation sources.
 6. Thephototherapeutic apparatus of claim 1 wherein the UV radiation sourcecomprises one or more LEDs configured to emit the UV radiation havingwavelengths between 290 nm and 305 nm.
 7. The phototherapeutic apparatusof claim 1 wherein the phototherapeutic apparatus is part of aphototherapy system, the phototherapy system comprising a user interfacecommunicatively coupled to the controller and configured to receiveuser-specific information related to parameters that affect vitamin Dsynthesis in a human patient.
 8. The phototherapeutic apparatus of claim7 wherein the user interface is directly coupled or wirelessly coupledto the phototherapeutic apparatus.
 9. The phototherapeutic apparatus ofclaim 1 wherein the controller is configured to receive user-specificinformation via a website or a smart phone application.
 10. Thephototherapeutic apparatus of claim 7 wherein the user interface isconfigured to receive feedback from the user regarding a previousphototherapy session provided by the phototherapeutic apparatus or aremote phototherapeutic apparatus communicatively coupled to the userinterface.
 11. A phototherapeutic apparatus, comprising: a housing; anultraviolet (UV) radiation assembly comprising: a plurality of lightemitting diodes (LEDs) carried by the housing; and a plurality ofreflectors forward of associated ones of the plurality of LEDs to directUV energy emitted by the plurality of LEDs generally forward toward anirradiation zone; and a controller communicatively coupled to the UVradiation assembly and configured to cause the phototherapeuticapparatus to limit a duration of an exposure period of a user in theirradiation zone based on a skin type of the user.
 12. Thephototherapeutic apparatus of claim 11 wherein the UV radiation assemblyfurther comprises a plurality of filters corresponding to the pluralityLEDs, the plurality of filters positioned between corresponding LEDs andthe irradiation zone.
 13. The phototherapeutic apparatus of claim 11wherein the controller is further configured to limit the duration ofthe exposure period based on a user-specific minimum erythemal dose(“MED”).
 14. The phototherapeutic apparatus of claim 11, wherein thephototherapeutic apparatus is part of a phototherapy system, thephototherapy system comprising a user interface communicatively coupledto the controller and configured to receive user-specific informationrelated to parameters that affect vitamin D synthesis in a humanpatient.
 15. The phototherapeutic apparatus of claim 14 wherein the userinterface is configured to receive feedback from the user regarding aprevious phototherapy session provided by the phototherapeutic apparatusor a remote phototherapeutic apparatus communicatively coupled thereto.16. A method of delivering ultraviolet (UV) radiation to stimulatevitamin D production via irradiation of skin, the method comprising:emitting UV energy with one or more light emitting diodes (LEDs) carriedby a housing of a phototherapeutic apparatus; directing, via one or morereflectors, the UV energy forward from the one or more LEDs toward anirradiation zone, wherein the UV energy transmitted from thephototherapeutic apparatus to the irradiation zone is within apredefined spectrum between 290 nm and 310 nm; terminating thetransmission of the UV energy after a user has been exposed to less thana user-specific minimum erythemal dose (“MED”) based on user-specificinformation.
 17. The method of claim 16, further comprising receivingthe user-specific information related to parameters that affect vitaminD synthesis in a human patient from a user interface communicativelycoupled to the phototherapeutic apparatus.
 18. The method of claim 16,further comprising filtering the UV energy with at least one filterpositioned between at least one of the LEDs and the irradiation zone.19. The method of claim 16 wherein the UV energy transmitted from thephototherapeutic apparatus to the irradiation zone is at leastsubstantially focused within at most a 10 nm spectrum centered at about297 nm.
 20. The method of claim 16, further comprising: receiving a userinput related to at least one of vitamin D dosage or skin type, whereinthe vitamin D dosage is an amount of vitamin D that stimulation by theUV energy is expected to produce in the skin of the human patient; andselecting a predetermined time period of the vitamin D dosage based onthe user input.